UTILIZATION OF TRITIATED WATER DILUTION TECHNIQUE IN DETERMINATION OF NITROGEN PARTITIONING IN CASHMERE GOATS

In order to investigate nitrogen partitioning in local cashmere goats,six Inner Mogolia White Cashmere goats between 2 to 2.5 years old were used to determine the nitrogen partitioning in cashmere goats.The total retained nitrogen(TN)in body,distribution of body nitrgen and hair nitrogen were measured by general digestive and metabolism method combined with tritiated water dilution technique.Results showed that the combined methods were ideal for determining body nitrgen(BN)and hair nitrogen(fur nitrogen,FN)of Cashmere goats.There were obvious significance between BN and FN in different seasons.In telogen,BN and FN partitioning was 75.7%±0.62% and 24.3%±0.62%,respectively.Whereas,it changed to 66.6%±2.2% and 33.4%±2.2% in anagen.BN partitioning decreased when the season changed from telogen to anagen,while FN partitioning increased,which indicated that more nitrogen substance was partitioned to body growth in telogen,and more nitrogen substance was distribute to cashmere growth in anagen.These transformation were related to the changing of photoperiod and some hormones,such as melatonin(MT),prolactin(PRL) and IGF-I.It could be concluded that tritiated water dilution technique can be used to detect body protein content as well as BN,combining general digestive and metabolism experiment,FN partitoning can be determined.BN and FN partitoning varied with the season in cashmere goats because of hormones changing.